Errors and Troubleshooting

Overview

Echo reports errors by category and usually includes a helpful hint.

Error Categories

Syntax Error

Common causes:

missing ;
missing )
missing ]
missing }
malformed function or loop syntax

Name Error

Common causes:

variable not declared
variable not visible in current scope
missing use or use mut
undefined function

Type Error

Common causes:

assigning wrong type to a declared variable
wrong function argument type
wrong return type
calling a built-in on the wrong kind of value

Execution Error

Common causes:

list index out of range
missing hash key
invalid method usage
invalid format() placeholder

Example

echo

count = 1;

Typical result: a name error because count was never declared.

Notes

In non-plain mode, some errors and warnings use Rich panels.
In plain mode, errors print as simple text.
The interpreter also prints hints for common mistakes.

Common Fixes

Declare variables before assignment
Add the missing semicolon
Add use or use mut inside functions
Check list and hash indexes
Match declared types

See Also